Over the years there have been many attempts to maximize the utility of power tools by providing various types of attachments which convert a tool from its primary function to a secondary function. One early example of just such an attempt is found in U.S. Pat. No. 2,544,461 in which an electric hand drill is fitted with a device which converts the drill into a sawing tool.
Various apparatuses have been proposed to convert chain saws into power drills. For instance, U.S. Pat. No. 2,489,772 provides an attachment which is driven by the sprocket of a chain saw and through a friction clutch powers a drilling tool. In U.S. Pat. No. 2,526,131 a massive boring device is mounted to the motor housing of a chain saw for use in boring chain holes in logs. Both of these devices require two workmen for safe operation, one on the boring side of the tool and one on the chain saw motor housing side. A chain saw attachment for operating rotatable tools is disclosed by U.S. Pat. No. 2,783,794 which employs a drive belt which is mounted on separate pulleys and runs parallel to the chain saw cutting chain.
It is an object of the present invention to provide a boring attachment which can readily be attached to or removed from the chain guide of a chain saw and converts the chain saw into a versatile and portable drilling tool which can be easily and safely operated by a single workman.